BACTerial Signal QUEnching of plant pathogens with Engineered enZymes – BACTSQUEEZ

Phytopathogenic bacteria are responsible for various diseases in plants including canker, soft rot and fireblight. Considering the economic impact of these pathogens as well as the emergence of antimicrobial resistance and the toxicity of chemical biocides, developing sustainable and environmentally friendly antibacterial solutions is urgently needed. Disrupting bacterial quorum sensing (QS), a communication system commonly used by phytopathogenic bacteria to regulate infection, is highly promising. One partner of the project has developed a robust enzyme, referred to as SsoPox, targeting QS of many plant pathogens relying on acyl-homoserine lactones (AHL). This enzyme, also known as lactonase, was first shown to disrupt the QS of P. aeruginosa, an opportunistic pathogen with high antibioresistance ability. In the continuity of these preliminary results, BactSqueez will face a new challenge by extending the QQ approach to the degradation of AHL involved in the QS of highly problematic phytopathogens (Dickeya sp., Agrobacterium sp., Pectobacterium sp.). Thanks to a multidisciplinary consortium involving both academic and industrial partners, BactSqueez will combine computational design, enzyme engineering and plant microbiology to develop improved lactonases that will be biochemically characterized and evaluated at both in vitro and in planta levels. Involving an industrial partner, the enzymes generated will then be considered for concrete applications to limit the use of phytopharmaceutical chemicals thanks to an innovative and sustainable alternative. Moreover, enzymes have not been considered for agricultural purpose so far, the lactonase-based solutions will thus be highly disruptive and pave the way for further development in the field.